1. Field of Art
The disclosure generally relates to the field of displaying animated images in a mobile web browser.
2. Description of the Related Art
Animated GIF files (Netscape, 1990s, Netscape Navigator 2.0) introduced the idea of putting a number of “frames” in a single file that could be played back successively at an interframe duration set in the file. Additionally, each frame could be used to update only a portion of the whole image to help in compression. This format, however, does not allow downloading images at a rate or bit encoding based on the observed network bandwidth.
JPEG format does not support animation, but using JavaScript to download a number of images and animate them is a widely used prior art. Most applications preload images all at once and use a JavaScript timer to playback the downloaded images. The concept of “streaming” the images in a network aware manner does not exist though.
Open source Java applets and JavaScript libraries are also widely available to support frame based animation. However, none of them addresses the issue of detecting network bandwidth to obtain the smoothest animation possible.
Network protocols such as Real Time Streaming Protocol (RTSP) use the concept of a media channel and a control channel. The control channel provides feedback to the server about the client's measurements of network performance. Transmission Control Protocol (TCP), on the other hand, starts a transmission to probe network capacity, and adjusts its transmission rate based on the observed behavior.